Merge branch 'release/0.9.0rc16' into develop
Adds distinctBy to typed pipe
Fixes small bug, change signature of distinctBy to make the default None reducers nicer. Add test
Strengthen test
Merge pull request #831 from twitter/feature/addDistinctBy

Adds distinctBy to typed pipe
Adds some comments to the TypedAPI
Merge pull request #832 from twitter/add-typeddocs

Adds some comments to the TypedAPI
Add TypedSimilarity.
Add TypedSimilarity from latest master.
Use Specification in test.
Address Oscar's comments.
Allow the scalding.flow.submitted.timestamp to be overridden
Revert "Allow the scalding.flow.submitted.timestamp to be overridden"

This reverts commit d637768cfecb96f1a7995a07fa64e6abecca32b4.
Allow the scalding.flow.submitted.timestamp to be overridden
Well that was a silly typo to leave in place
Fix indent
Merge pull request #834 from twitter/allow_submitted_ts_overridden

Allow the scalding.flow.submitted.timestamp to be overridden
Update to elephant-bird 4.4
Merge pull request #835 from twitter/update-eb

Update to elephant-bird 4.4
Update comments.